The composite term Gojirasaurus is derived from the name of the giant Japanese movie monster "Gojira" (Godzilla) and the Greek word "sauros" (σαυρος) meaning "lizard"; thus, "Godzilla lizard". In addition, a theropod dinosaur with the name Godzillasaurus exists in the Heisei era of Godzilla films. "Gojira" was selected as a reference to the great size of this theropod, which exceeded that of its Triassic counterparts. The specific name "quayi", is a reference to Quay County, New Mexico, where the holotype specimen was discovered. Gojirasaurus was described and named by Kenneth Carpenter in 1997 and the type species is Gojirasaurus quayi.